Standard engine for the machine, but note there was a very limited number (less than 5) constructed before development stopped.

Perhaps it is the elegant high-performance Mitsubishi Ki-83?
http://i1047.photobucket.com/albums/...t/ki-83-04.jpg

evansbe has it, it is the Mitsubishi Ki-83, which was so secret that the Allies didn't know about it until after the surrender, hence no familiar reporting name.

evansbe has control

Funny that, to quote Jenkins' post, (now deleted), .. "30 years later they produced a more useful twin engined aircraft". Indeed, as Mitsubishi produced the T-2 and F-2 twin engine jets, both very utile twin engined aircraft. Let us also not forget the MU-2, which was assembled in San Angelo, Texas, in the mid-1970s.

Here is another challenge:http://i1047.photobucket.com/albums/...ed139e351c.jpg

Looks like a RR Dart mounted over a low wing so I'm thinking HS748. However, the marking on the emergency exit makes me go for the Japanese look-alike.
NAMC YS-11?

Correct! The NAMC YS-11. Speed and range were similar to the HS 748, but the YS-11 had a greater payload capacity, thus a lower operating cost.

YOUR TURN.

OK. Here is a bigger engine and enough easy clues to work out to what aircraft it is attached.

http://i1313.photobucket.com/albums/...ps202c5659.jpg

Wild guess, Convair 880?

Not a Convair.
This is back in the 1960's. We were adjusting the fuel control unit with the engine running. That is why the fan is set in reverse but the hot end isn't.
Reduces the breeze a bit.

Pratt & Whitney JT3 on a B707?

That's the one.
JT3-MC6 engine on a Qantas B707.
Over to you.

Thanks Terry, only got there because I misidentified P&Ws logo on the cowling.

Try this bit of heavy metal:

http://i203.photobucket.com/albums/a...all14Jan15.jpg

It's a large US helicopter but I can't remember it's tribal name!:Oj

LOL, like it, I may try that ploy in the future!

Whoever can come up with the name, company or mil designation gets the kudos.

So why isn't it a JT3D engine instead?

Sikorsky S56. / CH37 Mojave

Zaxis has it

YHC & goodnight

Ooops!
You are right. It is a JT3D-MC6
I was feeling pleased that I could remember the last bit, as it is over 50 years ago! :ok:
It was the latest and greatest way back then, and my group held the record for the fastest engine change.
http://i1313.photobucket.com/albums/...ps4105924c.jpg

Try this...
http://i1024.photobucket.com/albums/...ps2a60eb72.jpg

Lycoming R680?